Package com.ibm.icu.text

Class DateTimePatternGenerator

  • All Implemented Interfaces:
    Freezable<DateTimePatternGenerator>, Cloneable
    public class DateTimePatternGenerator
extends Object
implements Freezable<DateTimePatternGenerator>, Cloneable
    This class provides flexible generation of date format patterns, like "yy-MM-dd". The user can build up the generator by adding successive patterns. Once that is done, a query can be made using a "skeleton", which is a pattern which just includes the desired fields and lengths. The generator will return the "best fit" pattern corresponding to that skeleton.

    The main method people will use is getBestPattern(String skeleton), since normally this class is pre-built with data from a particular locale. However, generators can be built directly from other data as well.

    • Constructor Detail

      • DateTimePatternGenerator

        protected DateTimePatternGenerator()
        Only for use by subclasses

    • Method Detail

      • getEmptyInstance

        public static DateTimePatternGenerator getEmptyInstance()
        Create empty generator, to be constructed with addPattern(...) etc.

      • getInstance

        public static DateTimePatternGenerator getInstance​(ULocale uLocale)
        Construct a flexible generator according to data for a given locale.
        Parameters:
        uLocale - The locale to pass.

      • getInstance

        public static DateTimePatternGenerator getInstance​(Locale locale)
        Construct a flexible generator according to data for a given locale.
        Parameters:
        locale - The JDK locale to pass.

      • getFrozenInstance

        @Deprecated
public static DateTimePatternGenerator getFrozenInstance​(ULocale uLocale)
        Deprecated.
        This API is ICU internal only.
        Construct a frozen instance of DateTimePatternGenerator for a given locale. This method returns a cached frozen instance of DateTimePatternGenerator, so less expensive than the regular factory method.
        Parameters:
        uLocale - The locale to pass.
        Returns:
        A frozen DateTimePatternGenerator.

      • getDefaultHourFormatChar

        @Deprecated
public char getDefaultHourFormatChar()
        Deprecated.
        This API is ICU internal only.

      • setDefaultHourFormatChar

        @Deprecated
public void setDefaultHourFormatChar​(char defaultHourFormatChar)
        Deprecated.
        This API is ICU internal only.

      • getAppendFormatNumber

        @Deprecated
public static int getAppendFormatNumber​(String string)
        Deprecated.
        This API is ICU internal only.

      • getBestPattern

        public String getBestPattern​(String skeleton)
        Return the best pattern matching the input skeleton. It is guaranteed to have all of the fields in the skeleton.

        Example code:{@.jcite com.ibm.icu.samples.text.datetimepatterngenerator.DateTimePatternGeneratorSample:---getBestPatternExample}

        Parameters:
        skeleton - The skeleton is a pattern containing only the variable fields. For example, "MMMdd" and "mmhh" are skeletons.
        Returns:
        Best pattern matching the input skeleton.

      • getBestPattern

        public String getBestPattern​(String skeleton,
                             int options)
        Return the best pattern matching the input skeleton. It is guaranteed to have all of the fields in the skeleton.
        Parameters:
        skeleton - The skeleton is a pattern containing only the variable fields. For example, "MMMdd" and "mmhh" are skeletons.
        options - MATCH_xxx options for forcing the length of specified fields in the returned pattern to match those in the skeleton (when this would not happen otherwise). For default behavior, use MATCH_NO_OPTIONS.
        Returns:
        Best pattern matching the input skeleton (and options).

      • addPattern

        public DateTimePatternGenerator addPattern​(String pattern,
                                           boolean override,
                                           DateTimePatternGenerator.PatternInfo returnInfo)
        Adds a pattern to the generator. If the pattern has the same skeleton as an existing pattern, and the override parameter is set, then the previous value is overridden. Otherwise, the previous value is retained. In either case, the conflicting information is returned in PatternInfo.

        Note that single-field patterns (like "MMM") are automatically added, and don't need to be added explicitly! *

        Example code:{@.jcite com.ibm.icu.samples.text.datetimepatterngenerator.DateTimePatternGeneratorSample:---addPatternExample}

        Parameters:
        pattern - Pattern to add.
        override - When existing values are to be overridden use true, otherwise use false.
        returnInfo - Returned information.

      • addPatternWithSkeleton

        @Deprecated
public DateTimePatternGenerator addPatternWithSkeleton​(String pattern,
                                                       String skeletonToUse,
                                                       boolean override,
                                                       DateTimePatternGenerator.PatternInfo returnInfo)
        Deprecated.
        This API is ICU internal only.
        addPatternWithSkeleton: If skeletonToUse is specified, then an availableFormats entry is being added. In this case: 1. We pass that skeleton to DateTimeMatcher().set instead of having it derive a skeleton from the pattern. 2. If the new entry's skeleton or basePattern does match an existing entry but that entry also had a skeleton specified (i.e. it was also from availableFormats), then the new entry does not override it regardless of the value of the override parameter. This prevents later availableFormats entries from a parent locale overriding earlier ones from the actual specified locale. However, availableFormats entries *should* override entries with matching skeleton whose skeleton was derived (i.e. entries derived from the standard date/time patters for the specified locale). 3. When adding the pattern (skeleton2pattern.put, basePattern_pattern.put), we set a field to indicate that the added entry had a specified skeleton.

      • getSkeleton

        public String getSkeleton​(String pattern)
        Utility to return a unique skeleton from a given pattern. For example, both "MMM-dd" and "dd/MMM" produce the skeleton "MMMdd".
        Parameters:
        pattern - Input pattern, such as "dd/MMM"
        Returns:
        skeleton, such as "MMMdd"

      • getSkeletonAllowingDuplicates

        @Deprecated
public String getSkeletonAllowingDuplicates​(String pattern)
        Deprecated.
        This API is ICU internal only.
        Same as getSkeleton, but allows duplicates
        Parameters:
        pattern - Input pattern, such as "dd/MMM"
        Returns:
        skeleton, such as "MMMdd"

      • getCanonicalSkeletonAllowingDuplicates

        @Deprecated
public String getCanonicalSkeletonAllowingDuplicates​(String pattern)
        Deprecated.
        This API is ICU internal only.
        Same as getSkeleton, but allows duplicates and returns a string using canonical pattern chars
        Parameters:
        pattern - Input pattern, such as "ccc, d LLL"
        Returns:
        skeleton, such as "MMMEd"

      • getBaseSkeleton

        public String getBaseSkeleton​(String pattern)
        Utility to return a unique base skeleton from a given pattern. This is the same as the skeleton, except that differences in length are minimized so as to only preserve the difference between string and numeric form. So for example, both "MMM-dd" and "d/MMM" produce the skeleton "MMMd" (notice the single d).
        Parameters:
        pattern - Input pattern, such as "dd/MMM"
        Returns:
        skeleton, such as "MMMdd"

      • getSkeletons

        public Map<String,​String> getSkeletons​(Map<String,​String> result)
        Return a list of all the skeletons (in canonical form) from this class, and the patterns that they map to.
        Parameters:
        result - an output Map in which to place the mapping from skeleton to pattern. If you want to see the internal order being used, supply a LinkedHashMap. If the input value is null, then a LinkedHashMap is allocated.

        Issue: an alternate API would be to just return a list of the skeletons, and then have a separate routine to get from skeleton to pattern.

        Returns:
        the input Map containing the values.

      • getBaseSkeletons

        public Set<String> getBaseSkeletons​(Set<String> result)
        Return a list of all the base skeletons (in canonical form) from this class

      • replaceFieldTypes

        public String replaceFieldTypes​(String pattern,
                                String skeleton)
        Adjusts the field types (width and subtype) of a pattern to match what is in a skeleton. That is, if you supply a pattern like "d-M H:m", and a skeleton of "MMMMddhhmm", then the input pattern is adjusted to be "dd-MMMM hh:mm". This is used internally to get the best match for the input skeleton, but can also be used externally.

        Example code:{@.jcite com.ibm.icu.samples.text.datetimepatterngenerator.DateTimePatternGeneratorSample:---replaceFieldTypesExample}

        Parameters:
        pattern - input pattern
        skeleton - For the pattern to match to.
        Returns:
        pattern adjusted to match the skeleton fields widths and subtypes.

      • replaceFieldTypes

        public String replaceFieldTypes​(String pattern,
                                String skeleton,
                                int options)
        Adjusts the field types (width and subtype) of a pattern to match what is in a skeleton. That is, if you supply a pattern like "d-M H:m", and a skeleton of "MMMMddhhmm", then the input pattern is adjusted to be "dd-MMMM hh:mm". This is used internally to get the best match for the input skeleton, but can also be used externally.
        Parameters:
        pattern - input pattern
        skeleton - For the pattern to match to.
        options - MATCH_xxx options for forcing the length of specified fields in the returned pattern to match those in the skeleton (when this would not happen otherwise). For default behavior, use MATCH_NO_OPTIONS.
        Returns:
        pattern adjusted to match the skeleton fields widths and subtypes.

      • setDateTimeFormat

        public void setDateTimeFormat​(String dateTimeFormat)
        The date time format is a message format pattern used to compose date and time patterns. The default value is "{1} {0}", where {1} will be replaced by the date pattern and {0} will be replaced by the time pattern.

        This is used when the input skeleton contains both date and time fields, but there is not a close match among the added patterns. For example, suppose that this object was created by adding "dd-MMM" and "hh:mm", and its datetimeFormat is the default "{1} {0}". Then if the input skeleton is "MMMdhmm", there is not an exact match, so the input skeleton is broken up into two components "MMMd" and "hmm". There are close matches for those two skeletons, so the result is put together with this pattern, resulting in "d-MMM h:mm".

        Parameters:
        dateTimeFormat - message format pattern, where {1} will be replaced by the date pattern and {0} will be replaced by the time pattern.

      • getDateTimeFormat

        public String getDateTimeFormat()
        Getter corresponding to setDateTimeFormat.
        Returns:
        pattern

      • setDecimal

        public void setDecimal​(String decimal)
        The decimal value is used in formatting fractions of seconds. If the skeleton contains fractional seconds, then this is used with the fractional seconds. For example, suppose that the input pattern is "hhmmssSSSS", and the best matching pattern internally is "H:mm:ss", and the decimal string is ",". Then the resulting pattern is modified to be "H:mm:ss,SSSS"
        Parameters:
        decimal - The decimal to set to.

      • getDecimal

        public String getDecimal()
        Getter corresponding to setDecimal.
        Returns:
        string corresponding to the decimal point

      • getRedundants

        @Deprecated
public Collection<String> getRedundants​(Collection<String> output)
        Deprecated.
        This API is ICU internal only.
        Redundant patterns are those which if removed, make no difference in the resulting getBestPattern values. This method returns a list of them, to help check the consistency of the patterns used to build this generator.
        Parameters:
        output - stores the redundant patterns that are removed. To get these in internal order, supply a LinkedHashSet. If null, a collection is allocated.
        Returns:
        the collection with added elements.

      • setAppendItemFormat

        public void setAppendItemFormat​(int field,
                                String value)
        An AppendItem format is a pattern used to append a field if there is no good match. For example, suppose that the input skeleton is "GyyyyMMMd", and there is no matching pattern internally, but there is a pattern matching "yyyyMMMd", say "d-MM-yyyy". Then that pattern is used, plus the G. The way these two are conjoined is by using the AppendItemFormat for G (era). So if that value is, say "{0}, {1}" then the final resulting pattern is "d-MM-yyyy, G".

        There are actually three available variables: {0} is the pattern so far, {1} is the element we are adding, and {2} is the name of the element.

        This reflects the way that the CLDR data is organized.

        Parameters:
        field - such as ERA
        value - pattern, such as "{0}, {1}"

      • getAppendItemFormat

        public String getAppendItemFormat​(int field)
        Getter corresponding to setAppendItemFormats. Values below 0 or at or above TYPE_LIMIT are illegal arguments.
        Parameters:
        field - The index to retrieve the append item formats.
        Returns:
        append pattern for field

      • setAppendItemName

        public void setAppendItemName​(int field,
                              String value)
        Sets the names of fields, eg "era" in English for ERA. These are only used if the corresponding AppendItemFormat is used, and if it contains a {2} variable.

        This reflects the way that the CLDR data is organized.

        Parameters:
        field - Index of the append item names.
        value - The value to set the item to.

      • getAppendItemName

        public String getAppendItemName​(int field)
        Getter corresponding to setAppendItemNames. Values below 0 or at or above TYPE_LIMIT are illegal arguments.
        Parameters:
        field - The index to get the append item name.
        Returns:
        name for field

      • isSingleField

        @Deprecated
public static boolean isSingleField​(String skeleton)
        Deprecated.
        This API is ICU internal only.
        Determines whether a skeleton contains a single field
        Parameters:
        skeleton - The skeleton to determine if it contains a single field.
        Returns:
        true or not

      • clone

        public Object clone()
        Boilerplate
        Overrides:
        clone in class Object
        Returns:
        a copy of this object.

      • skeletonsAreSimilar

        @Deprecated
public boolean skeletonsAreSimilar​(String id,
                                   String skeleton)
        Deprecated.
        This API is ICU internal only.
        Used by CLDR tooling; not in ICU4C. Note, this will not work correctly with normal skeletons, since fields that should be related in the two skeletons being compared - like EEE and ccc, or y and U - will not be sorted in the same relative place as each other when iterating over both TreeSets being compare, using TreeSet's "natural" code point ordering (this could be addressed by initializing the TreeSet with a comparator that compares fields first by their index from getCanonicalIndex()). However if comparing canonical skeletons from getCanonicalSkeletonAllowingDuplicates it will be OK regardless, since in these skeletons all fields are normalized to the canonical pattern char for those fields - M or L to M, E or c to E, y or U to y, etc. - so corresponding fields will sort in the same way for both TreeMaps.

      • getFields

        @Deprecated
public String getFields​(String pattern)
        Deprecated.
        This API is ICU internal only.
        internal routine
        Parameters:
        pattern - The pattern that is passed.
        Returns:
        field value